47 lines
1.5 KiB
Python
47 lines
1.5 KiB
Python
|
"""
|
||
|
|
Control character sets for terminal handling.
|
||
|
|
|
||
|
|
This module provides the control character sets used by the width() function to handle terminal
|
||
|
|
control characters.
|
||
|
|
"""
|
||
|
|
|
||
|
|
# Illegal C0/C1 control characters.
|
||
|
|
# These raise ValueError in 'strict' mode.
|
||
|
|
ILLEGAL_CTRL = frozenset(
|
||
|
|
chr(c) for c in (
|
||
|
|
list(range(0x01, 0x07)) + # SOH, STX, ETX (^C), EOT (^D), ENQ, ACK
|
||
|
|
list(range(0x10, 0x1b)) + # DLE through SUB (^Z)
|
||
|
|
list(range(0x1c, 0x20)) + # FS, GS, RS, US
|
||
|
|
[0x7f] + # DEL
|
||
|
|
list(range(0x80, 0xa0)) # C1 control characters
|
||
|
|
)
|
||
|
|
)
|
||
|
|
|
||
|
|
# Vertical movement control characters.
|
||
|
|
# These raise ValueError in 'strict' mode (indeterminate horizontal position).
|
||
|
|
VERTICAL_CTRL = frozenset({
|
||
|
|
'\x0a', # LF (line feed)
|
||
|
|
'\x0b', # VT (vertical tab)
|
||
|
|
'\x0c', # FF (form feed)
|
||
|
|
})
|
||
|
|
|
||
|
|
# Horizontal movement control characters.
|
||
|
|
# These affect cursor position and are tracked in 'strict' and 'parse' modes.
|
||
|
|
HORIZONTAL_CTRL = frozenset({
|
||
|
|
'\x08', # BS (backspace) - cursor left 1
|
||
|
|
'\x09', # HT (horizontal tab) - advance to next tab stop
|
||
|
|
'\x0d', # CR (carriage return) - cursor to column 0
|
||
|
|
})
|
||
|
|
|
||
|
|
# Terminal-valid zero-width control characters.
|
||
|
|
# These are allowed in all modes (zero-width, no movement).
|
||
|
|
ZERO_WIDTH_CTRL = frozenset({
|
||
|
|
'\x00', # NUL
|
||
|
|
'\x07', # BEL (bell)
|
||
|
|
'\x0e', # SO (shift out)
|
||
|
|
'\x0f', # SI (shift in)
|
||
|
|
})
|
||
|
|
|
||
|
|
# All control characters that need special handling (not regular printable).
|
||
|
|
ALL_CTRL = ILLEGAL_CTRL | VERTICAL_CTRL | HORIZONTAL_CTRL | ZERO_WIDTH_CTRL | {'\x1b'}
|